1. Field of the Invention
This invention relates to cosmetic and/or pharmaceutical formulations with increased viscosity and improved stability in storage which are distinguished by a content of selected esters of oligoglycerols with fatty acids as emulsifiers.
2. Discussion of Related Art
Emulsifiers are required for the permanent homogeneous mixing of substances which would otherwise be immiscible with one another. Esters of fatty acids with polyhydric alcohols, for example pentaerythritol, dipentaerythritol, or self-condensation products of glycerol, so-called technical oligoglycerol mixtures, are often used for this purpose in cosmetic and pharmaceutical formulations, for example for the production of cremes and notions. A review of this subject by G. Schuster and H. Pospischil was published in Arztl. Kosmetol., 11, 30-37 (1981).
The use of polyglycerol esters as o/w emulsifiers for cosmetic formulations is described, for example, in J. Soc. Cosmet. Chem. 28, 733-740 (1977) and in Fette, Seifen, Anstrichmittel 88, 101-106 (1986).
In addition, the use of selected polyglycerol fatty acid esters as cosmetic emulsifiers is claimed in DE-A1 40 05 819 and in DE-A1 40 23 593 (BASF). However, in cases where the esters based on unsaturated or saturated fatty acids mentioned in these documents are used, it has been found that the resulting emulsions are not always sufficiently stable in storage and/or are low in viscosity, i.e. have a viscosity which is not sufficiently high, so that problem-free dosing is difficult.
Accordingly, the problem addressed by the present invention was to provide new emulsifiers based on technical oligoglycerol mixtures and fatty acids which would not have any of the disadvantages mentioned above.